Explanations for forgetting: proactive and retroactive interference and retrieval failure due to absence of cues.

Explanations for Forgetting

Description, AO1, Explanations of Forgetting

Explanations for forgetting;

  1. Interference (Proactive and Retroactive)
  2. Cue-dependent forgetting (Context and State)


  1. Interference (IT)

The Interference Theory (IT) sees forgetting as due to information in the TLM becoming confused with or disrupted by other information during coding, leading to inaccurate recall. There are 2 forms of interference;

  • Proactive interference – Works forwards in time. This occurs when information stored previously interferes with an attempt to recall something new. (Old prevents new)

For example; the memory of your old mobile number disrupts attempts to recall your new mobile number.

  • Retroactive interference – Works backwards in time. This occurs when coding new information disrupts information stored previously. (New prevents old)

For example; the memory of a new car registration number prevents the recall of a previous one.

Interference is generally researched by getting participants to learn 2 lists of word pairs, where the first word of each pair on both lists is the same. Example of a word list used:

List A Lists B
Prince – Light Prince – Record
Sock – Bench Sock – Letter
Child – Moon Child – Gravel

Description, AO1- Research demonstrating retroactive interference – Schmidt et al (2000)


To assess the influence of retroactive interference upon the memory of street names learned during childhood.


  • 211 participants responded to a questionnaire sent out to a random selection 700 out of 1700 former students at a Dutch school, ranging in age from11 to 79 years old.
  • As part of the questionnaire, participants were given a map of the Molenberg neighbourhood (where they had gone to school) with all 48 street names replaced with numbers.
  • Participants were asked to remember as many of the street names as possible.
  • Other personal details collected included; how many times they had moved house, where they had lived and for how long, how often they had visited Molenberg.
  • The amount of retroactive interference experienced was assessed by the number of times the individual had moved to another neighbourhood or city (thus learning new sets of street names).


There was a positive association between the number of times participants had moved house outside the Molenberg neighbourhood and the number of street names they had forgotten.


The findings suggested that learning new patterns of street names when moving house makes remembering old patterns of street names harder to do. Retroactive interference does seem able to explain forgetting in some real-life situations.


Evaluation, AO3 of the Interference Theory


(1) Point: Support for the interference theory comes from Baddeley and Hitch who compared interference to trace decay as explanations for forgetting. Evidence:  Baddeley & Hitch asked participants, who played a varying numbers of rugby games, to remember as many opposition teams they’d played as possible. It was found that forgetting was due more to the amount of games played (interference) rather than time between each game (trace decay). Evaluation: This is a strength because it demonstrates that forgetting is more likely to be due to information in the LTM becoming confused, supporting the interference theory.


(2) Point: Support for the interference theory comes from Underwood and Postman who demonstrated retroactive interference. Evidence:  For example participants were divided into two groups. Group A were asked to learn a list of word pairs i.e. cat-tree, they were then asked to learn a second list of word pairs where the second paired word was different i.e. cat – glass. Group B were asked to learn the first list of word pairs only. Both groups were asked to recall the first list of word pairs. Underwood and Postman found that Group B recall of the first list was more accurate than the recall of group A. Evaluation: This is a strength because the research suggests that learning items in the second list interfered with participants’ ability to recall the list and therefore supports the existence of retroactive interference.


(1) Point: A weakness of the interference theory is that it is most commonly tested using laboratory experiments. Evidence:  For example, participants are often to complete artificial tasks, such as learning word lists, which lacks mundane realism and can result in participants displaying artificial behaviour. Evaluation: This is problematic as it means that any results from the lab experiments cannot be generalised to real-life forgetting which weakens those experiments as support for the interference theory.


2. Cue-dependent forgetting (CDF) – Description, AO1

This theory explains forgetting in the LTM as a retrieval failure: the information is stored in the LTM but cannot be accessed. Forgetting according to this theory is due to a lack of cues.

  1. Context-dependent failure (external cues – factors of the environment) – Description, AO1

Context dependent forgetting can occur when the environment during recall is different from the environment an individual was in when they were learning the information to be recalled.


Godden and Baddeley (1975) investigated the effect of environment on recall.


  • 18 divers from a diving club were asked to learn lists of 38 unrelated words of two or three syllables.
  • 4 conditions:
  • Learn on the LAND, recall on the LAND
  • Learn on the LAND, recall under WATER
  • Learn under WATER, recall on the LAND
  • Learn under WATER, recall under WATER



Baddeley under the sea results


The results show that the context acted as a cue to recall as the participants recalled more words when they learnt and recalled the words in the same environment than when they learnt and recalled the words in different environments.


Evaluation, AO3 of Cue-dependent forgetting (context dependent failure)

Forgetting occurs when the external environment is different at recall from how it was at coding. For example, getting fewer marks on a test when sitting the test in a room you are not familiar with compared to sitting the test in your usual classroom.


(1) Point: Support for context-dependent forgetting comes from Abernathy (1940). Evidence: Abernathy found that students performed better in tests if the tests took place in the same room as the learning of the material had taken place and if the tests were administered by the same instructor who had taught the information. Evaluation: This supports the theory of context-dependent forgetting because it shows that recall is worse when the coding and recall environment are different.

(2) Point: In addition, there was a high degree of control in Godden and Baddeley’s study. Evidence: For example, Godden and Baddeley were able to control in which environment the participants learned and recalled the words, in addition, they were also able to ensure that the difficulty of the word lists were controlled across the two conditions (this was particularly important as a repeated measures design as used and so the same list of words could not be used in both conditions). Evaluation: This is a strength because, such control over potential extraneous variables can be seen to allow a cause and effect relationship to be established and can increase internal validity.



(1) Point: However, the memory task in which the divers completed can be criticised as being artificial. Evidence: For example, in real life situations individuals don’t just use their memory to remember strings/lists of words. Individual memory is used to remember more complex pieces of information. Evaluation: This is a weakness because, it can be argued that Godden and Baddley’s memory test is not reflective of real-life memory. This means that the task is artificial and the findings can be criticsed for having low ecological validity (findings cannot be generalised to real life).


ii. State-dependent failure (internal cues) – Description, AO1

State dependent forgetting occurs when your mood or physiological state during recall is different from the mood you were in when you were learning.


___________ et al (1969) investigated the effect of internal cues on recall.



  • _____ ______ medical students participated on day 1 in a training sessions and on day 2 in a testing session.
  • The participants were _____________ assigned to four groups:
  • (SS) – sober on both days
  • (AA) – intoxicated on both days (alcohol)
  • (AS) – __________ on day 1, ____________ day 2
  • (SA) – ___________ on day 1, _______________ day 2
  • The intoxicated groups had 111mg/100ml of alcohol in their blood. They all showed signs of intoxication.
  • The participants had to perform 4 tests: an avoidance task, a verbal rote-learning task, a word-association test and a picture recognition task.


  • More errors were made on day 2 in the AS and SA conditions (rather than in the AA and SS conditions), however, this was not the case in the picture recognition task.
  • The SS participants performed the best in all tasks/tests.



The results support the state-dependent memory theory as the performance was best in the participants who were sober or intoxicated on both days (consistency of internal state).


Evaluation, AO3 of Cue-dependent forgetting (state dependent failure)


Recap: Forgetting occurs when an individual’s internal environment is dissimilar at recall to initial coding. For example, trying to remember information learned when sober while you are drunk.

(1) Point: Support for state-dependent forgetting comes from Overton (1972). Evidence: Overton (1972) carried out s study very similar to that of Goodwin (1969). They asked participants to learn material when either drunk or sober and found worse recall when participants were in a different internal state at recall to the internal state they were in at coding. Evaluation: This supports the theory of state-dependent forgetting because it shows that recall is worse when the individual’s internal state at coding and recall are different, suggesting that state-dependent forgetting is a valid explanation of forgetting.



(1) Point: However, the memory task in which the participants were asked to complete can be criticised as being artificial. Evidence: For example, _____________________________________________ _______________________________________________________________ _______________________________________________________________ _____________________________________________________________________ Evaluation: This is a weakness because, _______________________________________ __________________________________________________________________________________________________________________________________________


(2) Point: A further weakness is that the participant’s behaviours may have been affected by demand characteristics. Evidence: For example, ______________________________________________ ________________________________________________________________ ________________________________________________________________

_____________________________________________________________________Evaluation: This is a weakness because, _______________________________________ __________________________________________________________________________________________________________________________________________